[GRASS5] New USGS DEM data format

Rich Shepard rshepard at appl-ecosys.com
Wed Aug 1 19:26:46 EDT 2001


  I just learned that the US Geological Survey (USGS) has done two things
less than desirable. First, they no longer provide data for free, especially
the 30-m DEM data. It's only available now at one commercial site, that of
GeoComm (URL avaialable upon request).

  Second, and more importantly, they have changed the format of the
elevation data within the DEM to "decimal meters" which I assume to be
fractional meters. The elevations used to be only in integral feet or
meters. So, on this basis, more accurate DEM data is a Good Thing. But, they
changed the SDTS format to this, and ESRI's ARC/GIS-8 (and Maptitude-5.0)
are the only software that can read and translate the new SDTS format.
GeoComm, the only site at which these data are available, is an ESRI
reseller. Well, leaving out the politics of this arrangement, leaves my
question: can r.in.gdal handle the new format with the "decimal meter"
elevations?

  I've imported a DEM using r.in.gdal, and it didn't complain, but I've no
idea what elevation values it has. Anyone know? Frank?

Thanks,

Rich

Dr. Richard B. Shepard, President

                       Applied Ecosystem Services, Inc. (TM)
            2404 SW 22nd Street | Troutdale, OR 97060-1247 | U.S.A.
 + 1 503-667-4517 (voice) | + 1 503-667-8863 (fax) | rshepard at appl-ecosys.com
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